The present invention relates generally to sail vehicles and more particularly to a device for use on a sail vehicle for automatically adjusting the angular position of a sail on a sail vehicle to compensate for changes in wind pressure.
In most sail vehicles containing a sail supported by a mast and a boom, the angular position of the boom relative to the mast is set by a line connecting the boom to the hull or other part of the sale vehicle. Increased pressure on the sail caused by sudden wind gusts is most often compensated for by manually adjusting the length of the line. As is very well known, this arrangement is not always satisfactory or adequate, for one reason or another, causing the sail vehicle to keel exesssively and often tip over.
In U.S. Pat. No. 2,038,166 there is disclosed a sail attachment for bicycles comprising a supporting structure mounted on the bicycle, said supporting structure including a pair of spaced uprights, a mast mounted for swinging movement in a vertical plane between the uprights, means for releasably securing the mast in vertical position, a boom mounted for swinging movement in a horizontal plane on the uprights, and a sail mounted on the mast and the boom.
In U.S. Pat. No. 3,090,340 there is disclosed a device for a sailing vehicle including a sail, a boom for supporting the foot of said sail, a spar for supporting the luff of said sail, a mast for supporting said spar on said vehicle, a flexible joint connected to said mast and to said spar at a single point intermediate the ends of said spar, pressure yielding means for connecting said boom to said vehicle between a point adjacent the stern of said vehicle and a point aft of the center of said boom, and a second pressure yielding means for connecting the tack end of said boom to said vehicle whereby wind pressure on said sail tends to rotate the sail about an axial line between said flexible joint and the first mentioned pressure yielding means and about the axis of said spar.
In U.S. Pat. No. 3,968,765 there is disclosed an apparatus for rotatably mounting a sail on racing yachts, sailboats and sailsleds, which includes a step adapted to be mounted on the hull of the craft, a boom, rigging connecting the sail to the boom, adapted to enable setting of the sail-to-boom orientation, and means for connecting the boom to the step so that the boom, sail and rigging are substantially freely rotatable about the step, and so that the orientation of the sail is maintained at a substantially constant angle with respect to the direction of the shifting apparent wind, to enable the sail to respond directly to shifting winds without requiring manual supervision, in order to provide maximum thrust with minimum drag for substantially increased racing yacht speed capabilities. A keel is connected to the bottom of the hull to rotate about a vertical axis through the aft portion of the keel, in order to minimize racing yacht heeling and hydrodynamic drag. A rudder is rotatably connected to the stern, which includes a horizontal stabilizing fin oriented thereon so as to minimize racing yacht bucking by damping the yacht's response to choppy seas.
In U.S. Pat. No. 3,994,508 there is disclosed a sail arrangement having a hollow flexible boom with a short stiffener rod disposed therein near the forward end, and a stiffener tube which may be moved along the exterior of the boom. The flexible boom provides both automatic sail positioning and the spilling of excess wind during sudden strong gusts. In a second embodiment, a pivoted rigid boom is controlled by an elastic cord. In a third embodiment, a spring assembly permits the mast to pivot to spill the wind during strong gusts.
Another patent of interest is U.S. Pat. No. 4,047,493.
It is an object of this invention to provide a device for use in automatically adjusting the angular position of a sail in a sailing vehicle relative to a mast in said sailing vehicle supporting the sail in order to compensate for varying wind pressure.
It is another object of this invention to provide a device as described above which is selectively adjustable to react only to pressures above a desired amount.
It is further object of this invention to provide a device as described above which can be set so that it will not compensate for varying wind pressures.
It is still a further object of this invention to provide a device as described above which is easy to install, easy to use, and very reliable.
The foregoing and other objects and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawing which forms a part thereof, and in which is shown by way of illustration, a specific embodiment for practicing the invention. This embodiment will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.